Humidity and temperature insensitive organic conductor for electrophotographic screening process

Abstract

In accordance with the present invention, a method of electrophotographically manufacturing a luminescent screen assembly on an interior surface of a faceplate panel 17 of a color CRT 10 includes the steps of: coating the surface of the panel with a conductive solution to form a volatilizable organic conductive layer 32 , and overcoating the organic conductive layer 32 with a photoconductive solution to form a volatilizable photoconductive layer 34 . The conductive solution comprises the organic polymer 3,4-polyethylene dioxythiophene polystyrene sulphonate (PEDT/PSS); a methanol-soluble polymer or co-polymer selected from the group consisting of polyvinylpyrrolidone (PVP), poly (vinyl pyridine-co-vinyl acetate) (PVPy-VAc), polymethacrylic acid (PMAA), poly (hydroxyethylacrylate-co-methacrylic acid) (PHEA-MAA) and poly (hydroxyethyl methacrylate) (PHEMA) to reduce organic residue; and a solvent.

What is claimed is:  
     
       1. In a method of manufacturing a luminescent screen assembly on an interior surface of faceplate panel for a color CRT comprising the steps of coating said surface of said panel with a conductive solution to form a volatilizable organic conductive layer, and overcoating said organic conductive layer with a photoconductive solution to form a volatilizable photoconductive layer, the improvement wherein said conductive solution comprises: 3,4-polyethylene dioxythiophene polystyrene sulphonate (PEDT/PSS); a polymer or co-polymer selected from the group consisting of polyvinylpyrrolidone (PVP), poly (vinyl pyridine-co-vinyl acetate) (PVPy-VAc), polymethacrylic acid (PMAA), poly (hydroxyethylacrylate-co-methacrylic acid) (PHEA-MAA) and poly (2-hydroxyethyl methacrylate) (PHEMA); polyvinylbutyral (PVB) and a suitable solvent. 
     
     
       2. In a method of manufacturing a luminescent screen assembly on an interior surface of a faceplate panel for a color CRT, comprising the steps of: 
       a) coating said surface of said panel with a conductive solution to form a volatilizable organic conductive layer;  
       b) overcoating said organic conductive layer with a photoconductive solution to form a volatilizable organic photoconductive layer;  
       c) establishing a substantially uniform electrostatic charge on said photoconductive layer;  
       d) exposing selected areas of said photoconductive layer to actinic radiation to affect the charge thereon;  
       e) developing said photoconductive layer with at least one dry-powdered, light emitting, triboelectrically charged screen structure material;  
       f) fixing said screen structure material to said photoconductive layer to minimize displacement thereof;  
       g) filming said fixed screen structure material to form a film layer thereon;  
       h) aluminizing said filmed layer; and  
       i) baking said faceplate panel in air at a temperature of at least 450° C. to volatilize the constituents of said screen assembly, including said organic conductive layer, said organic photoconductive layer and said film layer, the improvement wherein said conductive solution comprises: 3,4-polyethylene dioxythiophene polystyrene sulphonate (PEDT/PSS); a polymer or co-polymer selected from the group consisting of polyvinylpyrrolidone (PVP), poly (vinyl pyridine-co-vinyl acetate) (PVPy-VAc), polymethacrylic acid (PMAA), poly (hydroxyethylacrylate-co-methacrylic acid) (PHEA-MAA), poly (hydroxyethyl methacrylate) (PHEMA) and polyvinylbutyral (PVB) to reduce residue after said baking step at 450° C.; and a suitable solvent.  
     
     
       3. The method as described in claim  2 , wherein said conductive solution further comprise a surfactant, an anti-foaming agent and deionized water.